Mineral Processing of Silver-carrying Bismuth Minerals from Yunnan

The gravity separation crude concentrate produced by a certain mine contains 17.9 g/t of silver, 1.15% of bismuth, and 23.42% of sulfur. 73.29% of the silver is present in bismuth minerals, with the main bismuth mineral being natural bismuth and a small amount being bismuthite. The sulfide minerals include pyrrhotite and pyrite, etc.. Objective To achieve efficient recovery of silver and bismuth elements in minerals simultaneously, based on the magnetic and floatability differences among minerals, Method the process flow of "medium magnetic separation of pyrrhotite - priority flotation of silver-loaded bismuth minerals - activation flotation of pyrite" was adopted. Lime was used to suppress pyrite, copper sulfate was used to activate silver-loaded bismuth minerals, and BIC and ZA were used to capture silver-loaded bismuth minerals. Results The full-process experiment yielded bismuth silver concentrate with a silver grade of 363.5 g/t, a silver recovery rate of 70.36%, a bismuth grade of 24.61%, and a bismuth recovery rate of 74.32%, a sulfur concentrate with a sulfur grade of 40.52% and a sulfur recovery rate of 71.11%, and pyrrhotite concentrate with a sulfur grade of 30.61% and a sulfur recovery rate of 22.15%. Conclusion The experiment achieved efficient separation among pyrrhotite, silver-loaded bismuth minerals, pyrite and gangvein, and efficiently recovered bismuth silver sulfur, providing technical support for the efficient comprehensive recovery of heavy separation concentrate.